This invention relates to a reforming apparatus for correcting a bend or warp in a work material to thereby reform it into a flat configuration, the reforming apparatus being used in combination with a pressing operation or the like.
A conventional reforming apparatus of the type described comprises a pair of upper and lower rows (usually, several to several tens) of reforming rolls arranged in staggered relation to each other, and these reforming rolls are driven to be rotated at the same speed to pass a work material (e.g. a material for a coil) through the upper and lower rows of rolls, so that the work material is repeatedly bent or deformed during the passage of the work material from an inlet side to an outlet side, thereby achieving a flatness precision required for the product.
The arrangement, pitch, diameter, number and etc., of the reforming rolls are determined by the thickness, width, yield point and etc., of the work material. Generally, the larger the number of the rolls with a smaller diameter is, the higher the accuracy of reforming is. However, in the manufacture of the apparatus, as a space for a bearing for the roll is reduced, the bearing load capacity is lowered, and also the allowable torque reduction of the roll shaft and a drive mechanism is limited, and therefore the increase of the number of the rolls is limited. Therefore, depending on the working accuracy required for the material, the diameter and number of the rolls are determined, taking the manufacturing cost into consideration.
In such a conventional reforming apparatus, however, since the material is repeatedly bent, the roll has sometimes been flexed, which adversely affects the flatness precision. In order to prevent such a flexing of the roll, there has been proposed an apparatus in which upper and lower rows of rolls are supported by back-up rolls, respectively. However, such an apparatus suffers from a problem that it is complicated in construction, and has an increased size.